(CNN) -- The World Health Organization is investigating an outbreak of hemorrhagic fever in northwestern Angola, it said Friday.

As of Thursday, 205 cases of Marburg hemorrhagic fever had been reported in the country, and 180 of those affected had died. Seven provinces have been affected, the latest being Zaire province, where six cases have been reported, the WHO said in its most recent update.

"It is a very, very dangerous and lethal virus in human beings," Mike Ryan, director of alert and response operations for WHO, told CNN. The virus -- in the same family as the Ebola virus -- spreads through blood and body fluid contact.

In this case -- only the second natural outbreak of the virus -- there is evidence it has been amplified through ineffective containment in hospitals, Ryan said.

According to WHO, the first large outbreak under natural conditions occurred from 1998-2000 in the Democratic Republic of Congo.

Some Angolans have taken their anxiety out on health workers.

Mobile surveillance teams in Uige were forced to suspend operations Thursday when vehicles were attacked and damaged by residents, the WHO said Friday. "As the situation has not improved, no surveillance teams were operational today in the province."

In addition, organization staff in Uige were notified Friday of several workers' fatalities, but teams were unable to investigate the causes of death or collect the bodies for burial. Discussions "to find urgent solutions" were under way with provincial authorities, the WHO said.

A WHO worker in Angola told CNN that health workers had been killed by residents who erroneously believed the workers were exposing them to the virus.

"The dramatic symptoms of Marburg hemorrhagic fever and its frequent fatality are resulting in a high level of fear, which is further aggravated by a lack of public understanding about the disease," the organization said. "Moreover, because the disease has no cure, hospitalization is not associated with a favorable outcome, and confidence in the medical care system has been eroded."

WHO said it has seen similar reactions during outbreaks of the Ebola virus. Two medical anthropologists are in Uige and will be joined by experts in social mobilization from Angola, the Democratic Republic of Congo and Mozambique.

Through the United Nations, WHO launched an appeal Friday for $2.4 million to support the emergency response to the outbreak. In addition, the organization has established an international network of laboratories to help in the investigation of this and other viral hemorrhagic fevers. They include two portable field laboratories in Angola.

"Sophisticated laboratory studies of the virus may help shed some light on certain unusual features of the outbreak, including the high fatality rate and the overwhelming concentration of initial cases in children under the age of five years," said a WHO statement.

A longer-term objective, the organization said, is to determine where the Marburg virus hides in nature between outbreaks. Studies of the Angolan virus may offer some clues.

Time to break out a copy of "The Hot Zone"... :shake:

AirForceChief

04-09-2005, 10:46 AM

Impress your friends and co-workers with these 'neat to know' facts:

Natural history and clinical features

Causative agent. Marburgvirus of the Filoviridae family.

Geographical occurrence. Outbreaks and sporadic cases have been reported in Angola, Democratic Republic of Congo, Kenya, and South Africa (in a person with a recent travel history to Zimbabwe). The initial outbreaks, in Germany and the former Yugoslavia in 1967, have been linked to laboratory work using African green monkeys (Cercopithecus aethiops) imported from Uganda.

Transmission. Transmission of the virus from person to person requires extremely close contact with a patient. Infection results from contact with blood or other body fluids (faeces, vomitus, urine, saliva, and respiratory secretions) with high virus concentration, especially when these fluids contain blood. Transmission via infected semen can occur up to seven weeks after clinical recovery.

Infection through casual contact is thought to be exceedingly rare. The low rate of transmission to persons with casual contact suggests that aerosol transmission via the respiratory tract is not efficient, if it occurs at all. Transmission does not occur during the incubation period.

Patients appear to be most infectious during the phase of severe illness accompanied by haemorrhagic manifestations. Close contact with a severely ill patient, during care at home or in hospital, and certain burial practices are common routes of infection. Transmission via contaminated injection equipment or through needle-stick injuries is associated with more severe disease, rapid deterioration, and possibly higher fatality.

Incubation period. 3 to 9 days.

Susceptibility. All age groups are susceptible to infection, but most cases have occurred in adults. Prior to the present outbreak in Angola, paediatric cases were considered extremely rare. In the largest outbreak previously recorded, which occurred in the Democratic Republic of Congo from late 1998 to 2000, only 12 (8%) of the cases were under the age of 5 years.

Clinical features. Illness caused by Marburg virus begins abruptly, with severe headache and severe malaise. Muscle aches and pains are a common feature.

A high fever usually appears on the first day of illness, followed by progressive and rapid debilitation. A severe watery diarrhoea, abdominal pain and cramping, nausea, and vomiting begin about the third day. Diarrhoea can persist for a week. The appearance of patients at this phase has been described as showing “ghost-like” drawn features, deep-set eyes, expressionless faces, and extreme lethargy. In the 1967 European outbreak, a non-itchy rash was a feature noted in most patients between days 2 and 7 after symptom onset.

Many patients develop severe haemorrhagic manifestations between days 5 and 7, and fatal cases usually have some form of bleeding, often from multiple sites. Findings of fresh blood in vomitus and faeces are often accompanied by bleeding from the nose, gums, and vagina. Spontaneous bleeding at venipuncture sites can be particularly troublesome. During the severe phase of illness, patients have sustained high fevers. Involvement of the central nervous system can result in confusion, irritability, and aggression. Orchitis has been reported occasionally in the late phase of disease (day 15).

In fatal cases, death occurs most often between 8 and 9 days after symptom onset, usually preceded by severe blood loss and shock.